Green bean plants with improved disease resistance

ABSTRACT

Green bean plants exhibiting resistance to  Sclerotinia sclerotiorum  are provided, together with methods of producing, identifying, or selecting plants or germplasm with a  Sclerotinia sclerotiorum  resistance phenotype and lacking an undesirable seed color trait. Such plants include green bean plants comprising introgressed genomic regions conferring disease resistance. Compositions, including novel polymorphic markers for detecting plants comprising introgressed disease resistance alleles, are further provided.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of priority of U.S. ProvisionalAppl. Ser. No. 62/792,814, filed Jan. 15, 2019, the disclosure of whichis hereby incorporated by reference in its entirety.

INCORPORATION OF SEQUENCE LISTING

A sequence listing containing the file named“SEMB036US-revised_ST25.txt” which is 8.0 kilobytes (measured inMS-Windows®) and created on Mar. 26, 2020, and comprises 26 sequences,is incorporated herein by reference in its entirety.

FIELD OF THE INVENTION

The present invention relates to the field of plant breeding and morespecifically to methods and compositions for producing bean plantsexhibiting improved disease resistance without linked deleterioustraits.

BACKGROUND

Disease resistance is an important trait in agriculture, particularlyfor the production of food crops. Although disease resistance alleleshave been identified in beans, efforts to introduce these alleles intocultivated lines have been hindered by a lack of specific markers linkedto the alleles, as well as the presence of deleterious allelesgenetically linked to disease resistance alleles that lead to anunacceptable reduction in yield, fruit size, and fruit quality. The useof marker-assisted selection (MAS) in plant breeding has made itpossible to select plants based on genetic markers linked to traits ofinterest. However, accurate markers for identifying or trackingdesirable traits in plants are frequently unavailable even if a geneassociated with the trait has been characterized. These difficulties arefurther complicated by factors such as polygenic or quantitativeinheritance, epistasis, and an incomplete understanding of the geneticbackground underlying expression of a desired phenotype. In the absenceof accurate and validated markers for use in MAS, it may not be feasibleto produce new plant lines exhibiting certain disease resistancephenotypes and acceptable yield, fruit size, and fruit quality.

SUMMARY

In one aspect, the present invention provides a green bean plantcomprising a recombinant chromosomal segment on chromosome 2, whereinsaid recombinant chromosomal segment comprises an allele conferringresistance to Sclerotinia sclerotiorum relative to a plant lacking saidrecombinant chromosomal segment. In some embodiments, said recombinantchromosomal segment comprises a marker locus selected from the groupconsisting of a marker locus M1 (SEQ ID NO: 1), marker locus M2 (SEQ IDNO: 7), and marker locus M3 (SEQ ID NO: 2) on chromosome 2. In certainembodiments, said plant further comprises a recombinant chromosomalsegment on chromosome 7, wherein said recombinant chromosomal segment onchromosome 7 comprises marker locus M9 (SEQ ID NO: 8) and marker locusM10 (SEQ ID NO: 14) or marker locus M11 (SEQ ID NO: 20) and marker locusM12 (SEQ ID NO: 26). In further embodiments, said recombinantchromosomal segment on chromosome 7 lacks a deleterious allelegenetically linked thereto that confers an undesirable color to a seedproduced by the plant. In yet further embodiments, said recombinantchromosomal segment comprises a favorable allele associated withdesirable seed color at marker locus M6 (SEQ ID NO: 15) and a favorableallele associated with Sclerotinia sclerotiorum resistance at markerlocus M1 (SEQ ID NO: 20) and marker locus M12 (SEQ ID NO: 26) onchromosome 7. In some embodiments, the green bean plant comprising arecombinant chromosomal segment on chromosome 2, wherein saidrecombinant chromosomal segment comprises an allele conferringresistance to Sclerotinia sclerotiorum relative to a plant lacking saidrecombinant chromosomal segment is further defined as an inbred orhybrid plant. In other embodiments, said Sclerotinia sclerotiorumresistance allele is located between 23,719,195 bp and 27,452,157 bp onchromosome 2 of the P. vulgaris reference genome sequence v. 1.0.

In another aspect, the present invention provides a green bean plantcomprising a recombinant chromosomal segment on chromosome 7, whereinsaid recombinant chromosomal segment comprises an allele conferringresistance to Sclerotinia sclerotiorum relative to a plant lacking saidrecombinant chromosomal segment. In one embodiment, said recombinantchromosomal segment comprises a marker locus selected from the groupconsisting of marker locus M11 (SEQ ID NO: 20), marker locus M8 (SEQ IDNO: 21), and marker locus M12 (SEQ ID NO: 26) on chromosome 7. Inanother embodiment, said recombinant chromosomal segment on chromosome 7lacks a deleterious allele genetically linked thereto that confers anundesirable color to a seed produced by the plant. In a furtherembodiment, said recombinant chromosomal segment comprises a favorableallele associated with desirable seed color at marker locus M6 (SEQ IDNO: 15) and a favorable allele associated with Sclerotinia sclerotiorumresistance at marker locus M11 (SEQ ID NO: 20) and marker locus M12 (SEQID NO: 26) on chromosome 7. In some embodiments, said introgressedSclerotinia sclerotiorum resistance allele is located between 42,414,123bp and 45,411,236 bp on chromosome 7 of the P. vulgaris reference genomesequence v. 1.0. In other embodiments, said green bean plant comprisinga recombinant chromosomal segment on chromosome 7, wherein saidrecombinant chromosomal segment comprises an allele conferringresistance to Sclerotinia sclerotiorum relative to a plant lacking saidrecombinant chromosomal segment is an inbred or hybrid. In a furtherembodiment, said plant comprises said chromosomal segment.

In another aspect, the present invention provides a recombinant DNAsegment comprising a Sclerotinia sclerotiorum resistance allele thatconfers to a plant increased resistance to Sclerotinia sclerotiorum,wherein the allele lacks a deleterious allele genetically linked theretothat confers to a plant undesirable seed color. In some embodiments,said Sclerotinia sclerotiorum resistance allele is derived from a plantof bean line G122 or A195. In other embodiments, said recombinant DNAsegment comprises a sequence selected from the group consisting of SEQID NOs: 15, 20, 21, and 26. In further embodiments, said recombinant DNAsegment is further defined as comprised within a plant, plant part,plant cell, or seed. In yet further embodiments, said DNA segmentconfers increased resistance to Sclerotinia sclerotiorum to said plant.

In another aspect, the present invention provides a method for producinga green bean plant with increased resistance to Sclerotinia sclerotiorumcomprising: crossing a green bean plant comprising a recombinantchromosomal segment on chromosome 2 or chromosome 7, wherein saidrecombinant chromosomal segment comprises an allele conferringresistance to Sclerotinia sclerotiorum relative to a plant lacking saidrecombinant chromosomal segment, with itself or with a second green beanplant of a different genotype to produce one or more progeny plants; andb) selecting a progeny plant comprising said Sclerotinia sclerotiorumresistance allele. In some embodiments, said selecting said progenyplant comprises detecting a marker locus genetically linked to saidSclerotinia sclerotiorum resistance allele. In other embodiments,selecting said progeny plant comprises detecting a marker locus withinor genetically linked to a chromosomal segment flanked in the genome ofsaid plant by: (a) marker locus M1 (SEQ ID NO: 1) and marker locus M2(SEQ ID NO: 7) on chromosome 2; (b) marker locus M9 (SEQ ID NO: 8) andmarker locus M10 (SEQ ID NO: 14) on chromosome 7; or (c) marker locusM11 (SEQ ID NO: 20) and marker locus M12 (SEQ ID NO: 26) on chromosome7; wherein said introgressed Sclerotinia sclerotiorum resistance alleleconfers to said plant increased resistance to Sclerotinia sclerotiorumcompared to a plant not comprising said allele, and wherein said plantlacks a deleterious allele genetically linked to said Sclerotiniasclerotiorum resistance allele that confers undesirable seed color tosaid plant when present. In some embodiments, selecting a progeny plantcomprises detecting nucleic acids comprising marker locus M1 (SEQ ID NO:1), marker locus M2 (SEQ ID NO: 7), marker locus M3 (SEQ ID NO: 2),marker locus M9 (SEQ ID NO: 8), marker locus M4 (SEQ ID NO: 9), markerlocus M10 (SEQ ID NO: 14), marker locus M6 (SEQ ID NO: 15), marker locusM11 (SEQ ID NO: 20), marker locus M8 (SEQ ID NO: 21), or marker locusM12 (SEQ ID NO: 26). In other embodiments, said Sclerotinia sclerotiorumresistance allele is identified by detecting a recurrent parent alleleat marker locus M6 (SEQ ID NO: 15), a non-recurrent parent allele atmarker locus M11 (SEQ ID NO: 20), and a non-recurrent parent allele atmarker locus M12 (SEQ ID NO: 26) on chromosome 7. In furtherembodiments, the progeny plant is an F2-F₆ progeny plant. In someembodiments, producing said progeny plant comprises backcrossing.

In one aspect, the present invention provides a method of producing aplant of a green bean line exhibiting resistance to Sclerotiniasclerotiorum , comprising introgressing into a plant a Sclerotiniasclerotiorum resistance allele within a recombinant chromosomal segmentflanked in the genome of said plant by: (a) marker locus M1 (SEQ IDNO: 1) and marker locus M2 (SEQ ID NO: 7) on chromosome 2; (b) markerlocus M9 (SEQ ID NO: 8) and marker locus M10 (SEQ ID NO: 14) onchromosome 7; or (c) marker locus M11 (SEQ ID NO: 20) and marker locusM12 (SEQ ID NO: 26) on chromosome 7; wherein said introgressedSclerotinia sclerotiorum resistance allele confers to said plantincreased resistance to Sclerotinia sclerotiorum compared to a plant notcomprising said allele, and wherein said plant lacks a deleteriousallele genetically linked to said Sclerotinia sclerotiorum resistanceallele that confers undesirable seed color to said plant when present.In some embodiments, said introgressed Sclerotinia sclerotiorumresistance allele is within a recombinant chromosomal segment flanked inthe genome of said plant by marker locus M1 (SEQ ID NO: 1) and markerlocus M2 (SEQ ID NO: 7) on chromosome 2, and wherein said plant furthercomprises a further introgressed Sclerotinia sclerotiorum resistanceallele within a recombinant chromosomal segment flanked in the genome ofsaid plant by marker locus M9 (SEQ ID NO: 8) and marker locus M10 (SEQID NO: 14) on chromosome 7 or marker locus M11 (SEQ ID NO: 20) andmarker locus M12 (SEQ ID NO: 26) on chromosome 7. In other embodiments,said recombinant chromosomal segment is flanked in the genome of saidplant by marker locus M11 (SEQ ID NO: 20) and marker locus M12 (SEQ IDNO: 26) on chromosome 7. In some embodiments, said recombinantchromosomal segment is defined by a recurrent parent allele at markerlocus M6 (SEQ ID NO: 15), a non-recurrent parent allele at marker locusM11 (SEQ ID NO: 20), and a non-recurrent parent allele at marker locusM12 (SEQ ID NO: 26) on chromosome 7. In other embodiments, saidintrogressing comprises backcrossing, marker-assisted selection, orassaying for said Sclerotinia sclerotiorum resistance. The inventionfurther provides green bean plants obtainable by the methods providedherein.

In another aspect, the present invention provides a method of selectinga green bean plant with increased resistance to Sclerotinia sclerotiorumcomprising: crossing a green bean plant comprising a recombinantchromosomal segment on chromosome 2 or chromosome 7, wherein saidrecombinant chromosomal segment comprises an allele conferringresistance to Sclerotinia sclerotiorum relative to a plant lacking saidrecombinant chromosomal segment, with itself or with a second green beanplant of a different genotype to produce one or more progeny plants; andb) selecting a progeny plant comprising said Sclerotinia sclerotiorumresistance allele. In some embodiments, selecting said progeny plantcomprises detecting a marker locus genetically linked to saidSclerotinia sclerotiorum resistance allele. In other embodiments,selecting said progeny plant comprises detecting a marker locus withinor genetically linked to a chromosomal segment flanked in the genome ofsaid plant by: (a) marker locus M1 (SEQ ID NO: 1) and marker locus M2(SEQ ID NO: 7) on chromosome 2; (b) marker locus M9 (SEQ ID NO: 8) andmarker locus M10 (SEQ ID NO: 14) on chromosome 7; or (c) marker locusM11 (SEQ ID NO: 20) and marker locus M12 (SEQ ID NO: 26) on chromosome7. In some embodiments, selecting a progeny plant comprises detectingnucleic acids comprising marker locus M1 (SEQ ID NO: 1), marker locus M2(SEQ ID NO: 7), marker locus M3 (SEQ ID NO: 2), marker locus M9 (SEQ IDNO: 8), marker locus M4 (SEQ ID NO: 9), marker locus M10 (SEQ ID NO:14), marker locus M6 (SEQ ID NO: 15), marker locus M11 (SEQ ID NO: 20),marker locus M8 (SEQ ID NO: 21), and marker locus M12 (SEQ ID NO: 26).In other embodiments, said progeny plant is an F₂-F₆ progeny plant. Infurther embodiments, producing said progeny plant comprisesbackcrossing.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1: Shows an overview of Sclerotinia sclerotiorum resistance QTLsand marker locations on chromosome 2.

FIG. 2: Shows an overview of Sclerotinia sclerotiorum resistance QTLsand marker locations on chromosome 7.

DETAILED DESCRIPTION

Common bean (Phaseolus vulgaris L.) is an important food crop worldwide.There are two main categories of beans sold as food: dry beans and green(or fresh) beans. The agricultural area allocated to each type isdifferent, with 29 million hectare for dry bean and only 2 millionhectare for green bean. However, the worldwide production is almost thesame, with 24 million tons for dry beans compared to 21 million tons forgreen beans. The two types of beans are also distinct agronomically. Drybeans and green beans are considered the same species, but the breedingand germplasm are very different since the desired end product forconsumption is distinct. The edible product of a dry bean cultivar isthe seed from the pod. Dry bean cultivars are developed to produce seedsthat are harvested at maturity and generally dried for storage and toincrease shelf life. In contrast, green bean cultivars are developed toproduce pods that are harvested prior to maturity. The edible product ofa green bean cultivar is the immature pod. Dry bean seeds varysignificantly in shape, size, and color depending on the type of drybean. Fresh or green beans generally vary in the size and shape of thepod.

Due to the significant number of differences in the desirable agronomictraits, breeding between the two gene pools generally leads toundesirable intermediate varieties that display traits that may beacceptable in dry beans but are undesirable in green beans. One suchtrait is seed color. In dry beans, variation in seed color is desirableas the color of the bean is used to distinguish between the bean types.However in green beans, white or colorless seeds are desirable sincegreen beans are often canned and colored seeds will cause the canningliquid to become dark. The white color is the result of the cotyledonsshining through a colorless seed coat. Breeders have kept the dry beanand green bean gene pools separate due to the large differences in theagronomic traits considered to be desirable for the two bean types. Infact, introgressing a trait from a dry bean variety into a green beanvariety is generally considered similar to introgressing a trait from awild species. Therefore, certain traits that are important for bothtypes, such as disease resistance, may be present in the dry bean genepool, but are not transferrable to or available for the green bean genepool.

White mold disease, which is caused by the fungus Sclerotiniasclerotiorum , affects over 400 plant species, including common bean.Sclerotinia sclerotiorum thrives in cool to moderate temperatures, whichis also the preferred environmental conditions for growing bean crops.Bean cultivars grown in these areas can come under heavy diseasepressure, which can lead to crop losses between 30-100%. Managementstrategies such as fungicide application can be combined with plantarchitecture traits such as tall, upright growth habit and porous canopyto prevent or reduce infection by Sclerotinia sclerotiorum under lowerdisease pressure. However, when disease pressure increases due to morefavorable environmental conditions, these measures are inadequate and itis essential that the bean cultivars include resistance againstSclerotinia sclerotiorum . In addition, resistant cultivars reduceand/or eliminate the use of fungicides.

Sclerotinia sclerotiorum resistance has been extensively studied in drybean. All known resistance sources are dry bean varieties and providequantitative resistance to Sclerotinia sclerotiorum. One commonlystudied source of Sclerotinia sclerotiorum resistance for dry bean isthe large-seeded Andean dry bean line G122. The publicly reported QTLregions that are responsible for Sclerotinia sclerotiorum resistance inG122 are located on chromosome 2 (WM2.2), chromosome 7 (WM7.1), andchromosome 8 (WM8.3). A QTL on chromosome 1 was also identified but thisQTL is believed to relate to disease avoidance associated with a moreresilient plant architecture rather than to physiological resistance.

The identification of resistance sources and resistance loci is only afirst step in developing resistant varieties. The trait must also betransferred from the source and incorporated into the relevant beancultivar, which is typically elite material. However, since the geneticdistance is high between the different bean types, there is a highlikelihood that undesired traits will be transferred along with thedesired trait from the source. Miklas et al. reported significant yieldloss and other drag phenotypes when attempting to introduce Sclerotiniasclerotiorum resistance from G122 into a pinto bean type, which is asmall seeded dry bean type. Due to the significant differences betweendry bean and green bean, it is likely that significant drag will occur.

Another aspect that further complicates identification of resistanceloci is that the results from the greenhouse straw test for white moldresistance and the results from field testing for white mold resistanceare not always consistent when compared. The greenhouse straw test andfield testing are the two main methods used to assay Sclerotiniasclerotiorum resistance. The straw test is often used because it isinexpensive, fast, and high throughput. Field testing provides morerealistic conditions, but is more time consuming and less accurate thanthe straw test. In addition, resistance observed in field tests mayresult from a combination of physiological resistance and diseaseavoidance, while the resistance observed in the straw test can beattributed to physiological resistance. It is preferable to identify andvalidate resistance QTLs through testing using both methods.

Although certain QTLs have been identified from dry bean, these have notbeen successfully used in green bean due to linkage drag associated withthe QTL. In particular, green bean breeders have reported commerciallyunacceptable seed color due to linkage associated with Sclerotiniasclerotiorum resistance introgressions. This is the result ofunfavorable alleles tightly linked to the allele of interest. In somecases, it is possible that unfavorable horticultural traits are evencaused by the gene of interest. In addition, recombination is oftensuppressed in regions that are introgressed from wild relatives,especially if those relatives are further removed genetically. In thecase of tightly linked deleterious traits the development of markers canhelp to assist the breeder in overcoming the unfavorable horticulturaltraits. In addition, recombination events can be developed to providebreeders with smaller introgressions of wild species DNA to be used in abreeding program.

The present inventors have made significant advancements in obtainingSclerotinia sclerotiorum resistance in green beans by identifying novelQTLs on chromosome 2 and chromosome 7 and developing novel recombinantchromosomal segments on chromosome 2 and chromosome 7. These QTLs aredistinct from those known in the art. In addition, the inventors havebroken the linkage between the resistance and the deleterious seed colortrait associated with Sclerotinia sclerotiorum resistance. As such,novel chromosomal segments that confer Sclerotinia sclerotiorumresistance without the deleterious seed color trait previouslyassociated with Sclerotinia sclerotiorum resistance on chromosome 7 areprovided. In addition, novel markers for the introgressed alleles areprovided, allowing the alleles to be accurately introgressed and trackedduring plant breeding. As such, the invention permits introgression ofthe disease resistance alleles into any desired green bean genotype.

In certain embodiments, plants are provided comprising an introgressedSclerotinia sclerotiorum resistance allele on chromosome 2, wherein saidallele confers to said plant increased resistance to Sclerotiniasclerotiorum compared to a plant not comprising the allele. In addition,plants are provided comprising an introgressed Sclerotinia sclerotiorumresistance allele on chromosome 7, wherein said allele confers to saidplant increased resistance to Sclerotinia sclerotiorum compared to aplant not comprising the allele. In further embodiments, said resistanceallele lacks a deleterious allele genetically linked thereto thatconfers undesirable seed color to said plant when present. In yetfurther embodiments, plants are provided comprising combinations ofintrogressed Sclerotinia sclerotiorum resistance alleles on chromosomes2 and 7, wherein said alleles lacks a deleterious allele geneticallylinked thereto that confers undesirable seed color to said plant whenpresent.

In some embodiments, said introgressed Sclerotinia sclerotiorumresistance allele is defined as located on chromosome 2 within arecombinant chromosomal segment flanked by marker locus M1 (SEQ IDNO: 1) and marker locus M2 (SEQ ID NO: 7). The invention furtherprovides marker locus M3 (SEQ ID NO: 2) as an interstitial markerbetween markers M1 and M2 that can be used to select the introgressedSclerotinia sclerotiorum resistance allele on chromosome 2. Marker locusM1 comprises a SNP change from A to T at 23,719,195 bp of version 1.0 ofthe public P. vulgaris reference genome sequence, marker locus M2comprises a SNP change from A to G at 27,452,157 bp of version 1.0 ofthe P. vulgaris reference genome sequence, and marker locus M3 comprisesa SNP change from A to G at 25,572,785 bp of version 1.0 of the P.vulgaris reference genome sequence.

In some embodiments, the introgressed Sclerotinia sclerotiorumresistance allele is defined as located on chromosome 7 within arecombinant chromosomal segment flanked by marker locus M9 (SEQ ID NO:8) and marker locus M10 (SEQ ID NO: 14) or marker locus M11 (SEQ ID NO:20) and marker locus M12 (SEQ ID NO: 26). The invention further providesmarker locus M4 (SEQ ID NO: 9) as an interstitial marker between markersM9 and M10. The invention further provides marker locus M8 (SEQ ID NO:21) as an interstitial marker between markers M11 and M12. The inventionfurther provides marker locus M6 (SEQ ID NO: 15) as a marker that can beused to select against the colored seed linkage drag. Marker locus M4comprises a SNP change from A to G at 2,281,649 bp of version 1.0 of thepublic P. vulgaris reference genome sequence, marker locus M6 comprisesa SNP change from T to G at 40,164,131 bp of version 1.0 of the P.vulgaris reference genome sequence, marker locus M8 comprises a SNPchange from A to C at 42,571,499 bp of version 1.0 of the P. vulgarisreference genome sequence, marker locus M9 comprises a SNP change from Ato G at 2,031,172 bp of version 1.0 of the P. vulgaris reference genomesequence, marker locus M10 comprises a SNP change from A to G at3,231,059 bp of version 1.0 of the P. vulgaris reference genomesequence, marker locus M11 comprises a SNP change from A to G at42,414,123 bp of version 1.0 of the P. vulgaris reference genomesequence, and marker locus M12 comprises a SNP change from A to C at45,411,236 bp of version 1.0 of the P. vulgaris reference genomesequence. The public genome of common bean is available at, for examplephaseolusgenes.bioinformatics.ucdavis.edu, and one skilled in the artwould understand how to locate the marker sequences provided for thefirst time in the instant application on any version (or later version)of the public genome.

In other embodiments, the invention provides plants comprising one ormore of the novel recombinant introgressions provided herein. Thesenovel introgressions provide robust resistance to Sclerotiniasclerotiorum , while avoiding the reduction in performancecharacteristics associated with conventional introgressions of theSclerotinia sclerotiorum resistance alleles. Methods of producing theplants described herein are further provided. The invention furtherprovides novel trait-linked markers which can be used to produce plantscomprising novel recombinant introgressions on chromosomes 2 and 7conferring Sclerotinia sclerotiorum resistance as described herein. Inparticular embodiments, the invention provides the markers shown inTable 4. Other embodiments of the invention provide markers M1 (SEQ IDNO: 1), M2 (SEQ ID NO: 7), M3 (SEQ ID NO: 2), M9 (SEQ ID NO: 8), M4 (SEQID NO: 9), M10 (SEQ ID NO: 14), M6 (SEQ ID NO: 15), M11 (SEQ ID NO: 20),M8 (SEQ ID NO: 21), and M12 (SEQ ID NO: 26), which have been shown to begenetically linked to Sclerotinia sclerotiorum resistance in plants.

The invention further provides reduced recombinant introgressionslacking the genomic locus of the Sclerotinia sclerotiorum resistancedonor at marker locus M6 (SEQ ID NO: 15), wherein said reduced genomicinterval lacks deleterious seed color alleles associated with largerSclerotinia sclerotiorum resistance introgressions.

Methods of producing plants comprising the reduced recombinantintrogressions described herein are further provided. In some examples,donor DNA from a resistant donor parent is introgressed into acultivated plant line (the recurrent parent line). M6 (SEQ ID NO: 15) isused to select the allele of the recurrent parent and M11 (SEQ ID NO:20) and M12 (SEQ ID NO: 26) are used to select the allele of theresistance donor parent resulting in a reduced genomic interval lackingdeleterious traits associated with larger Sclerotinia sclerotiorumresistance introgressions.

In certain embodiments, the invention provides methods of producing orselecting a green bean plant exhibiting resistance to Sclerotiniasclerotiorum comprising: a) crossing a green bean plant provided hereinwith itself or with a second green bean plant of a different genotype toproduce one or more progeny plants; and b) selecting a progeny plantcomprising said first introgressed allele or said second introgressedallele. In some embodiments, methods of the invention comprise selectinga progeny plant by detecting nucleic acids comprising marker locus M1(SEQ ID NO: 1), M2 (SEQ ID NO: 7), M3 (SEQ ID NO: 2), M9 (SEQ ID NO: 8),M4 (SEQ ID NO: 9), M10 (SEQ ID NO: 14), M6 (SEQ ID NO: 15), M11 (SEQ IDNO: 20), M8 (SEQ ID NO: 21), or M12 (SEQ ID NO: 26).

Because genetically diverse plant lines can be difficult to cross, theintrogression of Sclerotinia sclerotiorum resistance alleles intocultivated lines using conventional breeding methods could requireprohibitively large segregating populations for progeny screens with anuncertain outcome. Marker-assisted selection (MAS) is thereforeessential for the effective introgression of Sclerotinia sclerotiorumresistance alleles into elite cultivars. However, previously knownmarkers for Sclerotinia sclerotiorum resistance have failed todiscriminate between donor DNA conferring disease resistance and donorDNA conferring deleterious traits. This has been further complicated bythe previous inability to resolve the specific regions associated withdisease resistance. For the first time, the present invention enableseffective MAS by providing improved and validated markers for detectinggenotypes associated with disease resistance without the need to growlarge populations of plants to maturity in order to observe thephenotype.

I. Genomic Regions, Alleles, and Polymorphisms Associated WithSclerotinia sclerotiorum Resistance in Green Bean Plants

The invention provides novel introgressions of one or more allelesassociated with Sclerotinia sclerotiorum disease resistance without theundesirable seed color trait in green bean plants, together withpolymorphic nucleic acids and linked markers for tracking theintrogressions during plant breeding.

Dry bean lines exhibiting Sclerotinia sclerotiorum resistance are knownin the art and may be used together with the novel trait-linked markersprovided herein in accordance with certain embodiments of the invention.For example, the known and publicly available dry bean lines G122 andA195, can be used as sources for Sclerotinia sclerotiorum resistance.G122, which also carries the designations PI 163120 and “Jatu Rong,” ispublicly available from the U.S. National Plant Germplasm System. A195,which also carries the designation PI 643973, is publicly available fromthe U.S. National Plant Germplasm System.

Using the improved genetic markers and assays of the invention, thepresent inventors were able to successfully identify novel reducedintrogressions that confer Sclerotinia sclerotiorum resistance to theplant with fewer deleterious traits when introgressed into a green beanline. In certain embodiments, the invention provides green bean plantscomprising donor DNA between marker locus M1 (SEQ ID NO: 1) and markerlocus M2 (SEQ ID NO: 7) on chromosome 2, marker locus M9 (SEQ ID NO: 8)and marker locus M10 (SEQ ID NO: 14) on chromosome 7, or marker locusM11 (SEQ ID NO: 20) and marker locus M12 (SEQ ID NO: 26) on chromosome7.

The novel introgressions provided herein confer robust resistance toSclerotinia sclerotiorum, while avoiding the undesirable seed color seenwith conventional introgressions. The invention therefore represents asignificant advance in the art.

II. Introgression of Genomic Regions Associated with Sclerotiniasclerotiorum Resistance

Marker-assisted introgression involves the transfer of a chromosomalregion defined by one or more markers from a first genetic background toa second. Offspring of a cross that contain the introgressed genomicregion can be identified by the combination of markers characteristic ofthe desired introgressed genomic region from a first genetic backgroundand both linked and unlinked markers characteristic of the secondgenetic background.

The present invention provides novel accurate markers for identifyingand tracking introgression of one or more of the genomic regionsdisclosed herein from a Sclerotinia sclerotiorum resistant plant into acultivated line. The invention further provides markers for identifyingand tracking the novel introgressions disclosed herein during plantbreeding, including the markers set forth in Table 1.

Markers within or linked to any of the genomic intervals of the presentinvention may be useful in a variety of breeding efforts that includeintrogression of genomic regions associated with disease resistance intoa desired genetic background. For example, a marker within 40 cM, 20 cM,15 cM, 10 cM, 5 cM, 2 cM, or 1 cM of a marker associated with diseaseresistance described herein can be used for marker-assistedintrogression of genomic regions associated with a disease resistantphenotype.

Green bean plants comprising one or more introgressed regions associatedwith a desired phenotype wherein at least 10%, 25%, 50%, 75%, 90%, or99% of the remaining genomic sequences carry markers characteristic ofthe recurrent parent germplasm are also provided. Green bean plantscomprising an introgressed region comprising regions closely linked toor adjacent to the genomic regions and markers provided herein andassociated with a disease resistance phenotype are also provided.

III. Development of Disease Resistant Green Bean Varieties

For most breeding objectives, commercial breeders work with germplasmthat is “cultivated,” “cultivated type,” or “elite.” These cultivatedlines may be used as recurrent parents or as a source of recurrentparent alleles during breeding. Cultivated or elite germplasm is easierto breed because it generally performs well when evaluated forhorticultural performance. Many cultivated green bean types have beendeveloped and are known in the art as being agronomically elite andappropriate for commercial cultivation. However, the performanceadvantage a cultivated germplasm provides can be offset by a lack ofallelic diversity. Breeders generally accept this tradeoff becauseprogress is faster when working with cultivated material than whenbreeding with genetically diverse sources.

In contrast, when cultivated germplasm is crossed with non-cultivatedgermplasm, a breeder can gain access to novel alleles from thenon-cultivated type. Non-cultivated germplasm may be used as a source ofdonor alleles during breeding. However, this approach generally presentssignificant difficulties due to fertility problems associated withcrosses between diverse lines, and genetically linked deleteriousalleles from the non-cultivated parent. For example, non-cultivatedgreen bean types can provide alleles associated with disease resistance.However, these non-cultivated types may have poor horticulturalqualities such as poor quality, poor architecture, low yield, or smallfruit size.

The process of introgressing desirable resistance genes fromnon-cultivated lines into elite cultivated lines while avoiding problemswith genetically linked deleterious alleles or low heritability is along and often arduous process. In deploying alleles derived from wildrelatives it is often desirable to introduce a minimal or truncatedintrogression that provides the desired trait but lacks detrimentaleffects. To aid introgression reliable marker assays are preferable tophenotypic screens. Success is furthered by simplifying genetics for keyattributes to allow focus on genetic gain for quantitative traits suchas disease resistance. Moreover, the process of introgressing genomicregions from non-cultivated lines can be greatly facilitated by theavailability of accurate markers for MAS.

One of skill in the art would therefore understand that the alleles,polymorphisms, and markers provided by the invention allow the trackingand introduction of any of the genomic regions identified herein intoany genetic background. In addition, the genomic regions associated withdisease resistance disclosed herein can be introgressed from onegenotype to another and tracked using MAS. Thus, the inventors'discovery of accurate markers associated with disease resistance willfacilitate the development of green bean plants having beneficialphenotypes. For example, seed can be genotyped using the markers of thepresent invention to select for plants comprising desired genomicregions associated with disease resistance. Moreover, MAS allowsidentification of plants homozygous or heterozygous for a desiredintrogression.

Inter-species crosses can also result in suppressed recombination andplants with low fertility or fecundity. For example, suppressedrecombination has been observed for the tomato nematode resistance geneMi, the Mla and Mlg genes in barley, the Yr17 and Lr20 genes in wheat,the Runl gene in grapevine, and the Rina gene in peanut. Meioticrecombination is essential for classical breeding because it enables thetransfer of favorable alleles across genetic backgrounds, the removal ofdeleterious genomic fragments, and pyramiding traits that aregenetically tightly linked. Therefore, suppressed recombination forcesbreeders to enlarge segregating populations for progeny screens in orderto arrive at the desired genetic combination.

Phenotypic evaluation of large populations is time-consuming,resource-intensive and not reproducible in every environment.Marker-assisted selection offers a feasible alternative. Molecularassays designed to detect unique polymorphisms, such as SNPs, areversatile. However, they may fail to discriminate alleles within andamong bean species in a single assay. Structural rearrangements ofchromosomes such as deletions impair hybridization and extension ofsynthetically labeled oligonucleotides. In the case of duplicationevents, multiple copies are amplified in a single reaction withoutdistinction. The development and validation of accurate and highlypredictive markers are therefore essential for successful MAS breedingprograms.

IV. Marker Assisted Breeding and Genetic Engineering Techniques

Genetic markers that can be used in the practice of the presentinvention include, but are not limited to, restriction fragment lengthpolymorphisms (RFLPs), amplified fragment length polymorphisms (AFLPs),simple sequence repeats (SSRs), simple sequence length polymorphisms(SSLPs), single nucleotide polymorphisms (SNPs), insertion/deletionpolymorphisms (Indels), variable number tandem repeats (VNTRs), andrandom amplified polymorphic DNA (RAPD), isozymes, and other markersknown to those skilled in the art. Marker discovery and development incrop plants provides the initial framework for applications tomarker-assisted breeding activities (U.S. Patent Pub. Nos.:2005/0204780, 2005/0216545, 2005/0218305, and 2006/00504538). Theresulting “genetic map” is the representation of the relative positionof characterized loci (polymorphic nucleic acid markers or any otherlocus for which alleles can be identified) to each other.

Polymorphisms comprising as little as a single nucleotide change can beassayed in a number of ways. For example, detection can be made byelectrophoretic techniques including a single strand conformationalpolymorphism (Orita, et al. (1989) Genomics, 8(2), 271-278), denaturinggradient gel electrophoresis (Myers (1985) EPO 0273085), or cleavagefragment length polymorphisms (Life Technologies, Inc., Gaithersburg,Md.), but the widespread availability of DNA sequencing often makes iteasier to simply sequence amplified products directly. Once thepolymorphic sequence difference is known, rapid assays can be designedfor progeny testing, typically involving some version of PCRamplification of specific alleles (PASA; Sommer, et al. (1992)Biotechniques 12(1), 82-87), or PCR amplification of multiple specificalleles (PAMSA; Dutton and Sommer (1991) Biotechniques, 11(6),700-7002).

Polymorphic markers serve as useful tools for assaying plants fordetermining the degree of identity of lines or varieties (U.S. Pat. No.6,207,367). These markers form the basis for determining associationswith phenotypes and can be used to drive genetic gain. In certainembodiments of methods of the invention, polymorphic nucleic acids canbe used to detect in a bean plant a genotype associated with diseaseresistance, identify a green bean plant with a genotype associated withdisease resistance, and to select a green bean plant with a genotypeassociated with disease resistance. In certain embodiments of methods ofthe invention, polymorphic nucleic acids can be used to produce a greenbean plant that comprises in its genome an introgressed locus associatedwith disease resistance. In certain embodiments of the invention,polymorphic nucleic acids can be used to breed progeny green bean plantscomprising a locus or loci associated with disease resistance.

Genetic markers may include “dominant” or “codominant” markers.“Codominant” markers reveal the presence of two or more alleles (two perdiploid individual). “Dominant” markers reveal the presence of only asingle allele. Markers are preferably inherited in codominant fashion sothat the presence of both alleles at a diploid locus, or multiplealleles in triploid or tetraploid loci, are readily detectable, and theyare free of environmental variation, i.e., their heritability is 1. Amarker genotype typically comprises two marker alleles at each locus ina diploid organism. The marker allelic composition of each locus can beeither homozygous or heterozygous. Homozygosity is a condition whereboth alleles at a locus are characterized by the same nucleotidesequence. Heterozygosity refers to a condition where the two alleles ata locus are different.

Nucleic acid-based analyses for determining the presence or absence ofthe genetic polymorphism (i.e. for genotyping) can be used in breedingprograms for identification, selection, introgression, and the like. Awide variety of genetic markers for the analysis of geneticpolymorphisms are available and known to those of skill in the art. Theanalysis may be used to select for genes, portions of genes, QTL,alleles, or genomic regions that comprise or are linked to a geneticmarker that is linked to or associated with disease resistance in greenbean plants.

As used herein, nucleic acid analysis methods include, but are notlimited to, PCR-based detection methods (for example, TaqMan assays),microarray methods, mass spectrometry-based methods and/or nucleic acidsequencing methods, including whole genome sequencing. In certainembodiments, the detection of polymorphic sites in a sample of DNA, RNA,or cDNA may be facilitated through the use of nucleic acid amplificationmethods. Such methods specifically increase the concentration ofpolynucleotides that span the polymorphic site, or include that site andsequences located either distal or proximal to it. Such amplifiedmolecules can be readily detected by gel electrophoresis, fluorescencedetection methods, or other means.

One method of achieving such amplification employs the polymerase chainreaction (PCR) (Mullis et al. (1986) Cold Spring Harbor Symp. Quant.Biol. 51:263-273; European Patent 50,424; European Patent 84,796;European Patent 258,017; European Patent 237,362; European Patent201,184; U.S. Pat. Nos. 4,683,202; 4,582,788; and 4,683,194), usingprimer pairs that are capable of hybridizing to the proximal sequencesthat define a polymorphism in its double-stranded form. Methods fortyping DNA based on mass spectrometry can also be used. Such methods aredisclosed in U.S. Pat. Nos. 6,613,509 and 6,503,710, and referencesfound therein.

Polymorphisms in DNA sequences can be detected or typed by a variety ofeffective methods well known in the art including, but not limited to,those disclosed in U.S. Pat. Nos. 5,468,613, 5,217,863; 5,210,015;5,876,930; 6,030,787; 6,004,744; 6,013,431; 5,595,890; 5,762,876;5,945,283; 5,468,613; 6,090,558; 5,800,944; 5,616,464; 7,312,039;7,238,476; 7,297,485; 7,282,355; 7,270,981 and 7,250,252 all of whichare incorporated herein by reference in their entirety. However, thecompositions and methods of the present invention can be used inconjunction with any polymorphism typing method to detect polymorphismsin genomic DNA samples. These genomic DNA samples used include but arenot limited to, genomic DNA isolated directly from a plant, clonedgenomic DNA, or amplified genomic DNA.

For instance, polymorphisms in DNA sequences can be detected byhybridization to allele-specific oligonucleotide (ASO) probes asdisclosed in U.S. Pat. Nos. 5,468,613 and 5,217,863. U.S. Pat. No.5,468,613 discloses allele specific oligonucleotide hybridizations wheresingle or multiple nucleotide variations in nucleic acid sequence can bedetected in nucleic acids by a process in which the sequence containingthe nucleotide variation is amplified, spotted on a membrane and treatedwith a labeled sequence-specific oligonucleotide probe.

Target nucleic acid sequence can also be detected by probe ligationmethods, for example as disclosed in U.S. Pat. No. 5,800,944 wheresequence of interest is amplified and hybridized to probes followed byligation to detect a labeled part of the probe.

Microarrays can also be used for polymorphism detection, whereinoligonucleotide probe sets are assembled in an overlapping fashion torepresent a single sequence such that a difference in the targetsequence at one point would result in partial probe hybridization(Borevitz et al., Genome Res. 13:513-523 (2003); Cui et al.,Bioinformatics 21:3852-3858 (2005). On any one microarray, it isexpected there will be a plurality of target sequences, which mayrepresent genes and/or noncoding regions wherein each target sequence isrepresented by a series of overlapping oligonucleotides, rather than bya single probe. This platform provides for high throughput screening ofa plurality of polymorphisms. Typing of target sequences bymicroarray-based methods is described in U.S. Pat. Nos. 6,799,122;6,913,879; and 6,996,476.

Other methods for detecting SNPs and Indels include single baseextension (SBE) methods. Examples of SBE methods include, but are notlimited, to those disclosed in U.S. Pat. Nos. 6,004,744; 6,013,431;5,595,890; 5,762,876; and 5,945,283.

In another method for detecting polymorphisms, SNPs and Indels can bedetected by methods disclosed in U.S. Pat. Nos. 5,210,015; 5,876,930;and 6,030,787 in which an oligonucleotide probe having a 5′ fluorescentreporter dye and a 3′ quencher dye covalently linked to the 5′ and 3′ends of the probe. When the probe is intact, the proximity of thereporter dye to the quencher dye results in the suppression of thereporter dye fluorescence, e.g. by Forster-type energy transfer. DuringPCR, forward and reverse primers hybridize to a specific sequence of thetarget DNA flanking a polymorphism while the hybridization probehybridizes to polymorphism-containing sequence within the amplified PCRproduct. In the subsequent PCR cycle DNA polymerase with 5′→3′exonuclease activity cleaves the probe and separates the reporter dyefrom the quencher dye resulting in increased fluorescence of thereporter.

In another embodiment, a locus or loci of interest can be directlysequenced using nucleic acid sequencing technologies. Methods fornucleic acid sequencing are known in the art and include technologiesprovided by 454 Life Sciences (Branford, Conn.), Agencourt Bioscience(Beverly, Mass.), Applied Biosystems (Foster City, Calif.), LI-CORBiosciences (Lincoln, Nebr.), NimbleGen Systems (Madison, Wis.),Illumina (San Diego, Calif.), and VisiGen Biotechnologies (Houston,Tex.). Such nucleic acid sequencing technologies comprise formats suchas parallel bead arrays, sequencing by ligation, capillaryelectrophoresis, electronic microchips, “biochips,” microarrays,parallel microchips, and single-molecule arrays.

Various genetic engineering technologies have been developed and may beused by those of skill in the art to introduce traits in plants. Incertain aspects of the claimed invention, traits are introduced intobean plants via altering or introducing a single genetic locus ortransgene into the genome of a variety or progenitor thereof. Methods ofgenetic engineering to modify, delete, or insert genes andpolynucleotides into the genomic DNA of plants are well-known in theart.

In specific embodiments of the invention, improved bean lines can becreated through the site-specific modification of a plant genome.Methods of genetic engineering include, for example, utilizingsequence-specific nucleases such as zinc-finger nucleases (see, forexample, U.S. Pat. Appl. Pub. No. 2011-0203012); engineered or nativemeganucleases; TALE-endonucleases (see, for example, U.S. Pat. Nos.8,586,363 and 9,181,535); and RNA-guided endonucleases, such as those ofthe CRISPR/Cas systems (see, for example, U.S. Pat. Nos. 8,697,359 and8,771,945 and U.S. Pat. Appl. Pub. No. 2014-0068797). One embodiment ofthe invention thus relates to utilizing a nuclease or any associatedprotein to carry out genome modification. This nuclease could beprovided heterologously within donor template DNA for templated-genomicediting or in a separate molecule or vector. A recombinant DNA constructmay also comprise a sequence encoding one or more guide RNAs to directthe nuclease to the site within the plant genome to be modified. Furthermethods for altering or introducing a single genetic locus include, forexample, utilizing single-stranded oligonucleotides to introduce basepair modifications in a bean plant genome (see, for example Sauer etal., Plant Physiol, 170(4):1917-1928, 2016).

Methods for site-directed alteration or introduction of a single geneticlocus are well-known in the art and include those that utilizesequence-specific nucleases, such as the aforementioned, or complexes ofproteins and guide-RNA that cut genomic DNA to produce a double-strandbreak (DSB) or nick at a genetic locus. As is well-understood in theart, during the process of repairing the DSB or nick introduced by thenuclease enzyme, a donor template, transgene, or expression cassettepolynucleotide may become integrated into the genome at the site of theDSB or nick. The presence of homology arms in the DNA to be integratedmay promote the adoption and targeting of the insertion sequence intothe plant genome during the repair process through homologousrecombination or non-homologous end joining (NHEJ).

In another embodiment of the invention, genetic transformation may beused to insert a selected transgene into a plant of the invention ormay, alternatively, be used for the preparation of transgenes which canbe introduced by backcrossing. Methods for the transformation of plantsthat are well-known to those of skill in the art and applicable to manycrop species include, but are not limited to, electroporation,microprojectile bombardment, Agrobacterium-mediated transformation, anddirect DNA uptake by protoplasts.

To effect transformation by electroporation, one may employ eitherfriable tissues, such as a suspension culture of cells or embryogeniccallus or alternatively one may transform immature embryos or otherorganized tissue directly. In this technique, one would partiallydegrade the cell walls of the chosen cells by exposing them topectin-degrading enzymes (pectolyases) or mechanically wound tissues ina controlled manner.

An efficient method for delivering transforming DNA segments to plantcells is microprojectile bombardment. In this method, particles arecoated with nucleic acids and delivered into cells by a propellingforce. Exemplary particles include those comprised of tungsten,platinum, and preferably, gold. For the bombardment, cells in suspensionare concentrated on filters or solid culture medium. Alternatively,immature embryos or other target cells may be arranged on solid culturemedium. The cells to be bombarded are positioned at an appropriatedistance below the macroprojectile stopping plate.

An illustrative embodiment of a method for delivering DNA into plantcells by acceleration is the Biolistics Particle Delivery System, whichcan be used to propel particles coated with DNA or cells through ascreen, such as a stainless steel or Nytex screen, onto a surfacecovered with target cells. The screen disperses the particles so thatthey are not delivered to the recipient cells in large aggregates.Microprojectile bombardment techniques are widely applicable, and may beused to transform virtually any plant species.

Agrobacterium-mediated transfer is another widely applicable system forintroducing gene loci into plant cells. An advantage of the technique isthat DNA can be introduced into whole plant tissues, thereby bypassingthe need for regeneration of an intact plant from a protoplast. ModernAgrobacterium transformation vectors are capable of replication in E.coli as well as Agrobacterium, allowing for convenient manipulations(Klee et al., Nat. Biotechnol., 3(7):637-642, 1985). Moreover, recenttechnological advances in vectors for Agrobacterium-mediated genetransfer have improved the arrangement of genes and restriction sites inthe vectors to facilitate the construction of vectors capable ofexpressing various polypeptide coding genes. The vectors described haveconvenient multi-linker regions flanked by a promoter and apolyadenylation site for direct expression of inserted polypeptidecoding genes. Additionally, Agrobacterium containing both armed anddisarmed Ti genes can be used for transformation.

In those plant strains where Agrobacterium-mediated transformation isefficient, it is the method of choice because of the facile and definednature of the gene locus transfer. The use of Agrobacterium-mediatedplant integrating vectors to introduce DNA into plant cells is wellknown in the art (Fraley et al., Nat. Biotechnol., 3:629-635, 1985; U.S.Pat. No. 5,563,055).

Transformation of plant protoplasts also can be achieved using methodsbased on calcium phosphate precipitation, polyethylene glycol treatment,electroporation, and combinations of these treatments (see, for example,Potrykus et al., Mol. Gen. Genet., 199:183-188, 1985; Omirulleh et al.,Plant Mol. Biol., 21(3):415-428, 1993; Fromm et al., Nature,312:791-793, 1986; Uchimiya et al., Mol. Gen. Genet., 204:204, 1986;Marcotte et al., Nature, 335:454, 1988). Transformation of plants andexpression of foreign genetic elements is exemplified in Choi et al.(Plant Cell Rep., 13:344-348, 1994), and Ellul et al. (Theor. Appl.Genet., 107:462-469, 2003).

V. Definitions

The following definitions are provided to better define the presentinvention and to guide those of ordinary skill in the art in thepractice of the present invention. Unless otherwise noted, terms are tobe understood according to conventional usage by those of ordinary skillin the relevant art.

As used herein, the term “plant” includes plant cells, plantprotoplasts, plant cells of tissue culture from which green bean plantscan be regenerated, plant calli, plant clumps and plant cells that areintact in plants or parts of plants such as pollen, flowers, seeds,leaves, stems, and the like.

As used herein, the term “population” means a genetically heterogeneouscollection of plants that share a common parental derivation.

As used herein, the terms “variety” and “cultivar” mean a group ofsimilar plants that by their genetic pedigrees and performance can beidentified from other varieties within the same species.

As used herein, an “allele” refers to one of two or more alternativeforms of a genomic sequence at a given locus on a chromosome.

A “quantitative trait locus” (QTL) is a chromosomal location thatencodes for at least a first allele that affects the expressivity of aphenotype.

As used herein, a “marker” means a detectable characteristic that can beused to discriminate between organisms. Examples of such characteristicsinclude, but are not limited to, genetic markers, biochemical markers,metabolites, morphological characteristics, and agronomiccharacteristics.

As used herein, the term “phenotype” means the detectablecharacteristics of a cell or organism that can be influenced by geneexpression.

As used herein, the term “genotype” means the specific allelic makeup ofa plant.

As used herein, “elite” or “cultivated” variety means any variety thathas resulted from breeding and selection for superior agronomicperformance. An “elite plant” refers to a plant belonging to an elitevariety. Numerous elite varieties are available and known to those ofskill in the art of green bean breeding. An “elite population” is anassortment of elite individuals or varieties that can be used torepresent the state of the art in terms of agronomically superiorgenotypes of a given crop species, such as green bean. Similarly, an“elite germplasm” or elite strain of germplasm is an agronomicallysuperior germplasm.

As used herein, the term “introgressed,” when used in reference to agenetic locus, refers to a genetic locus that has been introduced into anew genetic background, such as through backcrossing. Introgression of agenetic locus can be achieved through plant breeding methods and/or bymolecular genetic methods. Such molecular genetic methods include, butare not limited to, various plant transformation techniques and/ormethods that provide for homologous recombination, non-homologousrecombination, site-specific recombination, and/or genomic modificationsthat provide for locus substitution or locus conversion.

As used herein, the terms “recombinant” or “recombined” in the contextof a chromosomal segment refer to recombinant DNA sequences comprisingone or more genetic loci in a configuration in which they are not foundin nature, for example as a result of a recombination event betweenhomologous chromosomes during meiosis.

As used herein, the term “linked,” when used in the context of nucleicacid markers and/or genomic regions, means that the markers and/orgenomic regions are located on the same linkage group or chromosome suchthat they tend to segregate together at meiosis.

As used herein, “tolerance locus” means a locus associated withtolerance or resistance to disease. For instance, a tolerance locusaccording to the present invention may, in one embodiment, controltolerance or susceptibility to Sclerotinia sclerotiorum.

As used herein, “tolerance” or “improved tolerance” in a plant refers tothe ability of the plant to perform well, for example by maintainingyield, under disease conditions. Tolerance may also refer to the abilityof a plant to maintain a plant vigor phenotype under disease conditions.Tolerance is a relative term, indicating that a “tolerant” plant is moreable to maintain performance compared to a different (less tolerant)plant (e.g. a different plant variety) grown in similar diseaseconditions. One of skill will appreciate that plant tolerance to diseaseconditions varies widely, and can represent a spectrum of more-tolerantor less-tolerant phenotypes. However, by simple observation, one ofskill can generally determine the relative tolerance of differentplants, plant varieties, or plant families under disease conditions, andfurthermore, will also recognize the phenotypic gradations of“tolerance.”

As used herein “resistance” or “improved resistance” in a plant todisease conditions is an indication that the plant is more able toreduce disease burden than a non-resistant or less resistant plant.Resistance is a relative term, indicating that a “resistant” plant ismore able to reduce disease burden compared to a different (lessresistant) plant (e.g., a different plant variety) grown in similardisease conditions. One of skill will appreciate that plant resistanceto disease conditions varies widely, and can represent a spectrum ofmore-resistant or less-resistant phenotypes. However, by simpleobservation, one of skill can generally determine the relativeresistance of different plants, plant varieties, or plant families underdisease conditions, and furthermore, will also recognize the phenotypicgradations of “resistant.”

As used herein, “resistance allele” means the nucleic acid sequenceassociated with tolerance or resistance to disease.

The term “about” is used to indicate that a value includes the standarddeviation of error for the device or method being employed to determinethe value. The use of the term “or” in the claims is used to mean“and/or” unless explicitly indicated to refer to alternatives only orthe alternatives are mutually exclusive, although the disclosuresupports a definition that refers to only alternatives and to “and/or.”When used in conjunction with the word “comprising” or other openlanguage in the claims, the words “a” and “an” denote “one or more,”unless specifically noted. The terms “comprise,” “have” and “include”are open-ended linking verbs. Any forms or tenses of one or more ofthese verbs, such as “comprises,” “comprising,” “has,” “having,”“includes” and “including,” are also open-ended. For example, any methodthat “comprises,” “has” or “includes” one or more steps is not limitedto possessing only those one or more steps and also covers otherunlisted steps. Similarly, any plant that “comprises,” “has” or“includes” one or more traits is not limited to possessing only thoseone or more traits and covers other unlisted traits.

EXAMPLES Example 1

Preliminary Mapping of Sclerotinia sclerotiorum Resistance in Green Bean

To map Sclerotinia sclerotiorum resistance in green bean, a recombinantinbred line (RIL) population was generated from the cross of Valentino,a large-sieve green bean for the fresh and processing market that issusceptible to Sclerotinia sclerotiorum with the resistant dry bean lineG122. This population was advanced to the F6 generation by single seeddescent. Two phenotypic evaluations of the F6:9 families consisting of281 RILs were included in the QTL analysis. The phenotypic trials wereperformed in the greenhouse using a random complete block design. Inaddition, a field trial was conducted with a 3-replication randomcomplete block design. The F₆ population was genotyped using a GoldenGate fingerprinting platform. Over 600 markers were identified andmapped to a reference map.

Subsequently, a QTL analysis was performed using a variety ofapproaches, including single-marker regression, non-parametric intervalmapping model, and composite interval mapping. This analysis resulted intwo QTL peaks, located on chromosome 2 (WMS_2), chromosome 7 (WMS_7),respectively. There were two QTL peaks on chromosome 7, which are ˜25 cMapart from each other. Due to a large gap of ˜10 cM in between, therewere not enough recombination events to determine if the two peaksrepresent one large QTL or two smaller separate QTLs. As a result, theaccurate positions of these two QTLs are difficult to estimate by eitherinterval mapping or marker regression.

Example 2

Validation of Sclerotinia sclerotiorum Resistance Loci

The QTLs on chromosomes 2 and 7 were subsequently validated using therecurrent parent line Valentino. The two peaks located on chromosome 7were investigated as two separate QTLs (WMS_7.1 and WMS_7.2). Linescontaining a single QTL, as well as all possible combinations of QTLs,were developed to validate the effectiveness of single QTLs as well astheir level of interaction (Table 1).

TABLE 1 Overview of the lines created to validate the efficacy of theQTLs WMS_2 WMS_7.1 WMS_7.2 Line 1 R R R Line 2 R R S Line 3 R S R Line 4R S S Line 5 S R R Line 6 S R S Line 7 S S R Line 8 S S S

Each line was developed by backcrossing to the recurrent parent at least3 times, then selfed at least 3 times, using markers for each backcrossand selfing generation to track each QTL. All lines were from the sameBC3F2 plant to ensure maximum similarity of background genotype. Allpopulations were tested using the greenhouse seedling test. Plants wereinoculated ˜9 days after planting and scored for disease ˜33 days afterplanting. The experimental design was a randomized complete block designwith 36 reps, where each rep was one tray on a bench containing 12 pots,with one plant per pot. In addition, the lines were also tested usingthe greenhouse straw test. For this experiment, the design was arandomized complete block design with 18 reps, one pot per entry perrep, with the pot containing two subsamples that were averaged to give aSclerotinia sclerotiorum resistance score. In this test, plants arescored at an older stage than in the seedling test, but younger thanplants scored in the field trial.

Analysis of the data was performed using SAS/JMP software. An ANOVA wasrun on each QTL to determine the significance of effect on Sclerotiniasclerotiorum resistance, with the QTL as a fixed effect and the rep as arandom effect. The percent of variation explained by each QTL, by rep,and by error, was estimated using PROC VARCOMP. LS Means of individualQTLs and QTL combinations were compared to assess additive effects. Allthree QTLs were confirmed in the greenhouse setting (Table 2).

TABLE 2 Summary of validation results for the greenhouse experimentWMS_2 WMS_7.1 WMS_7.2 Validation Valentino Valentino ValentinoBackground Significant? Yes Yes Yes R² 47% 9% 35%

The eight fixed BC₃F₃ lines were tested in the field. In addition to theoriginal background line Valentino, a second background line, PINDJV1012(a Pinto type dry bean line), was used to validate the QTLs. Lineshaving the PINDJV1012 background were created in the same way as thosehaving the Valentino background. Since each entry is a sibling from thesame BC3F2 plant, the entries are “Near Isogenic Lines,” meaning theyshould contain the same genetic background and only vary at the QTL.This was confirmed using fingerprinting. The lines were screened in thefield in a randomized complete block design experiment with 10replications. Plots were ˜10′ in length and sown with 60 seed per plot.Scoring was done on green plants with developing beans (a few weeksafter flowering) on a per plot (not per plant) basis on a 1-9 scale,with 1 being total resistance and 9 being complete susceptibility (totaldeath of plot). An ANOVA was run in JMP to determine whether each QTLwas significant. A mixed model was used including all QTLs to determinewhether any multiplicative effects (QTL interactions) were occurring toindicate epistatic effects. No QTL interactions were observed. In thefield setting, only the WMS_2 on chromosome 2 and WMS_7.1 on chromosome7 could be confirmed (Table 3).

TABLE 3 Summary of the validation experiment in the field WMS_2 WMS_7.1WMS_7.2 Validation Pinto, Pinto, Pinto, Background Valentino ValentinoValentino Significant? Yes, Yes Yes, No No, No R² 41-48% 30% —

Example 3

Fine Mapping of Identified Sclerotinia sclerotiorum Resistance Loci

After validating the resistance loci, a mapping population was createdto further define the QTL regions on chromosome 2 and on chromosome 7.For the QTL on chromosome 2, the Valentino (susceptible parent) x G122(resistance donor) cross was used to develop a BC₄F₃ population andfamilies that showed recombination events within the rough mapped QTLregions were selected. To avoid the influence of epistatic effectsbetween resistance loci, only populations having one resistance locuswere used for mapping. The selected lines were fixed through selfing tocreate near-isogenic sister lines (NILs). 14 sister lines were chosenfor analysis. These lines were phenotyped for Sclerotinia sclerotiorumresistance using the straw method in the greenhouse. Further genotypingidentified a genomic region between markers M1 (SEQ ID NO: 1) and M2(SEQ ID NO: 7) that conferred the resistance to Sclerotinia sclerotiorum(FIG. 1). Marker M3 (SEQ ID NO: 2) was identified as a trait-linkedmarker for selection of the resistance locus on chromosome 2.

Further mapping of the loci on chromosome 7 was done through acomparative analysis within lines. 26 lines were selected from the BC₃F₅generation that were heterozygous in the region that encompasses bothQTLs on chromosome 7. These lines were selfed to generate a BC₃F₆generation and for each line two selections were kept for furtheranalysis. These selections were lines in which one line was homozygousfor the resistant donor allele and the other line was homozygous for thesusceptible parent allele in that location. These ‘mirror’ lines werethen phenotyped for their level of Sclerotinia sclerotiorum resistance.Subsequently, the fine mapped location of the resistance QTL onchromosome 7 was determined by comparing the recombination breakpoint inpairs that differed significantly in their Sclerotinia sclerotiorumresistance with the breakpoint in those that did not differsignificantly. This led to two significant QTL regions on chromosome 7(FIG. 2). The first (designated WMS_7.1) is located between markers M9(SEQ ID NO: 8) and M10 (SEQ ID NO: 14) and the second (designatedWMS_7.2) is located between markers M11 (SEQ ID NO: 20) and M12 (SEQ IDNO: 26). In addition, marker M4 (SEQ ID NO: 9) was found within the QTLregion of WMS_7.1, while marker M8 (SEQ ID NO: 21) was found within theQTL region of WMS_7.2. Markers M4 and M8 can be used in addition to theboundary markers to select for the resistance QTLs.

Example 4 Removal of Deleterious Seed Color Trait

32 BC₅F₃ lines (Valentino/G122) and 22 BC₃F₃ lines (Golddust/G122) weredeveloped for breeding using Sclerotinia sclerotiorum resistance markerson chromosomes 2 and 7. These lines were tested for horticultural traitsand Sclerotinia sclerotiorum resistance using the greenhouse straw test.It was found that 49 of these events had a dark seed phenotype whileonly 5 events had the desirable white seed phenotype. Subsequently, allthe F₉ Valentino/G122 lines in the RIL population used to map theSclerotinia sclerotiorum resistance QTLs from G122 were phenotyped forseed color. It was found that the seed color locus is closely linked toQTL WMS_7.2 on chromosome 7 (FIG. 2). The marker, M6 (SEQ ID NO: 15),was 97% predictive of white seed coat color (TT) and 100% predictive ofnon-white seed coat color (GG or GT).

Marker M6 was also tested in a diverse panel of 265 inbred lines todetermine the predictability of the marker in a broader population.Marker M6 was found to be 94% predictive of the white seed coat colorphenotype but was only 46% predictive of the non-white seed coat colorphenotype. In a subsequent panel of 138 lines, including material fromboth the A195 and G122 donors, a 100% predictive efficacy of marker M6for white/non-white seed coat color was observed. The marker istherefore most effective for breaking the color linkage from theSclerotinia sclerotiorum resistance QTLs on chromosome 7. Markers fortracking the resistance QTLs and seed color phenotype are shown in Table4.

TABLE 4 List of markers and favorable alleles at each marker fortracking resistance QTLs and seed color Public Marker Fwd Rev Geneticposition Public Marker sequence primer primer Probe 1 Probe 2 MarkerPosition marker position size SNP Favorable (SEQ ID (SEQ (SEQ (SEQ (SEQname Chr. (cM) (bp) SNP (bp) (bp) change allele NO) ID NO) ID NO) ID NO)ID NO) M1 2 46.49 23,719,154- 23,719,195 101 [A/T] T (G122) 1 23,719,255M3 2 48.23 25,572,635- 25,572,785 301 [A/G] A (G122) 2 3 4 5 625,572,935 M2 2 50.43 27,451,992- 27,452,157 237 [A/G] A (G122) 727,452,228 M9 7 29.72 2,031,172 121 [A/G] A (G122) 8 M4 7 31.742,281,589- 2,281,649 121 [A/G] G (G122) 9 10 11 12 13 2,281,709 M10 738.42 3,231,059 121 [A/G] G (G122) 14 M6 7 59.07 40,164,095- 40,164,13197 [T/G] T (white) 15 16 17 18 19 40,164,190 M11 7 63.40 42,414,123 326[A/G] G (G122) 20 M8 7 64.03 42,571,439- 42,571,499 121 [A/C] C (G122)21 22 23 24 25 42,571,559 M12 7 69.45 45,411,236 121 [A/C] A (G122) 26

Example 5

Identification of Alternative Sources of Sclerotinia sclerotiorumResistance

Sclerotinia sclerotiorum resistance QTLs were identified and mapped inresistant line A195. A195 is a dry bean variety developed by Shree Singh(Singh et al., 2007). Previous work in dry bean showed that A195contains two independent complementary genes controlling resistance toSclerotinia sclerotiorum and that there is one dominant resistance genedifference between G122 and A195 (Viteri & Singh, 2015). To assess theefficacy of Sclerotinia sclerotiorum resistance from A195 in green bean,a cross was made between A195 and the green bean line “Banga”.Recombinant inbred populations were developed and the QTL analysis wasperformed on the F7:8 populations. The populations were phenotyped usinga greenhouse assay. The genotyping was performed using a high-throughputgenotyping system utilizing over 3000 markers. F₈ bulk seed from 138families were screened to determine F₇ genotypes. Of the 3000+ markers,1205 were informative and used in the subsequent QTL analysis. The QTLanalysis identified two QTLs: one on chromosome 2 at the same locationas the G122 locus on chromosome 2 and one on chromosome 7. The QTL onchromosome 7 spanned a large region covering both the WMS_7.1 andWMS_7.2 regions found in G122.

To determine if the resistance QTLs of A195 and those of G122 aredifferent, a comparative genotyping study was performed. This studyshowed that A195 was identical over a range of 260 markers on chromosome7, including the resistance QTL regions. This indicates that theresistance QTLs of A195 and G122 are identical on chromosome 7. Similarresults were found for the Sclerotinia sclerotiorum resistance QTL WMS_2on chromosome 2.

1. A green bean plant comprising a recombinant chromosomal segment onchromosome 2 or chromosome 7, wherein said recombinant chromosomalsegment comprises an allele conferring resistance to Sclerotiniasclerotiorum relative to a plant lacking said recombinant chromosomalsegment.
 2. The plant of claim 1, wherein said recombinant chromosomalsegment comprises a marker locus selected from the group consisting of amarker locus M1 (SEQ ID NO: 1), marker locus M2 (SEQ ID NO: 7), andmarker locus M3 (SEQ ID NO: 2) on chromosome
 2. 3. The plant of claim 2,wherein said plant further comprises a recombinant chromosomal segmenton chromosome 7, wherein said recombinant chromosomal segment onchromosome 7 comprises marker locus M9 (SEQ ID NO: 8) and marker locusM10 (SEQ ID NO: 14) or marker locus M11 (SEQ ID NO: 20) and marker locusM12 (SEQ ID NO: 26).
 4. The plant of claim 3, wherein said recombinantchromosomal segment on chromosome 7 lacks a deleterious allelegenetically linked thereto that confers an undesirable color to a seedproduced by the plant.
 5. The plant of claim 4, wherein said recombinantchromosomal segment comprises a favorable allele associated withdesirable seed color at marker locus M6 (SEQ ID NO: 15) and a favorableallele associated with Sclerotinia sclerotiorum resistance at markerlocus M11 (SEQ ID NO: 20) and marker locus M12 (SEQ ID NO: 26) onchromosome
 7. 6. The plant of claim 1, defined as an inbred or hybridplant.
 7. The plant of claim 1, wherein said Sclerotinia sclerotiorumresistance allele is located between 23,719,195 bp and 27,452,157 bp onchromosome 2 of the P. vulgaris reference genome sequence v. 1.0.
 8. Theplant of claim 1, defined as comprising said recombinant chromosomalsegment on chromosome 7, wherein said recombinant chromosomal segmentcomprises an allele conferring resistance to Sclerotinia sclerotiorumrelative to a plant lacking said recombinant chromosomal segment.
 9. Theplant of claim 8, wherein (a) said recombinant chromosomal segmentcomprises a marker locus selected from the group consisting of markerlocus M11 (SEQ ID NO: 20), marker locus M8 (SEQ ID NO: 21), and markerlocus M12 (SEQ ID NO: 26) on chromosome 7; (b) said recombinantchromosomal segment on chromosome 7 lacks a deleterious allelegenetically linked thereto that confers an undesirable color to a seedproduced by the plant; or (c) said recombinant chromosomal segmentcomprises a favorable allele associated with desirable seed color atmarker locus M6 (SEQ ID NO: 15) and a favorable allele associated withSclerotinia sclerotiorum resistance at marker locus M11 (SEQ ID NO: 20)and marker locus M12 (SEQ ID NO: 26) on chromosome 7; or (d) saidintrogressed Sclerotinia sclerotiorum resistance allele is locatedbetween 42,414,123 bp and 45,411,236 bp on chromosome 7 of the P.vulgaris reference genome sequence v. 1.0. 10-12. (canceled)
 13. Theplant of claim 8, defined as an inbred or hybrid plant.
 14. A plant partof the plant of claim 8, wherein the plant comprises said recombinantchromosomal segment.
 15. A recombinant DNA segment comprising aSclerotinia sclerotiorum resistance allele that confers to a plantincreased resistance to Sclerotinia sclerotiorum, wherein the allelelacks a deleterious allele genetically linked thereto that confers to aplant undesirable seed color.
 16. The recombinant DNA segment of claim15, wherein said Sclerotinia sclerotiorum resistance allele is derivedfrom a plant of bean line G122 or A195.
 17. The recombinant DNA segmentof claim 15, wherein said recombinant DNA segment comprises a sequenceselected from the group consisting of SEQ ID NOs: 15, 20, 21, and 26.18. The recombinant DNA segment of claim 15, further defined ascomprised within a plant, plant part, plant cell, or seed.
 19. Therecombinant DNA segment of claim 18, wherein said DNA segment confersincreased resistance to Sclerotinia sclerotiorum to said plant.
 20. Amethod for producing a green bean plant with increased resistance toSclerotinia sclerotiorum comprising: a) crossing the plant of claim 1with itself or with a second green bean plant of a different genotype toproduce one or more progeny plants; and b) selecting a progeny plantcomprising said Sclerotinia sclerotiorum resistance allele.
 21. Themethod of claim 20, wherein selecting said progeny plant comprisesdetecting a marker locus genetically linked to said Sclerotiniasclerotiorum resistance allele.
 22. The method of claim 21, whereinselecting said progeny plant comprises detecting a marker locus withinor genetically linked to a chromosomal segment flanked in the genome ofsaid plant by: (a) marker locus M1 (SEQ ID NO: 1) and marker locus M2(SEQ ID NO: 7) on chromosome 2; (b) marker locus M9 (SEQ ID NO: 8) andmarker locus M10 (SEQ ID NO: 14) on chromosome 7; or (c) marker locusM11 (SEQ ID NO: 20) and marker locus M12 (SEQ ID NO: 26) on chromosome7; wherein said introgressed Sclerotinia sclerotiorum resistance alleleconfers to said plant increased resistance to Sclerotinia sclerotiorumcompared to a plant not comprising said allele, and wherein said plantlacks a deleterious allele genetically linked to said Sclerotiniasclerotiorum resistance allele that confers undesirable seed color tosaid plant when present.
 23. The method of claim 21, wherein selecting aprogeny plant comprises detecting nucleic acids comprising marker locusM1 (SEQ ID NO: 1), marker locus M2 (SEQ ID NO: 7), marker locus M3 (SEQID NO: 2), marker locus M9 (SEQ ID NO: 8), marker locus M4 (SEQ ID NO:9), marker locus M10 (SEQ ID NO: 14), marker locus M6 (SEQ ID NO: 15),marker locus M11 (SEQ ID NO: 20), marker locus M8 (SEQ ID NO: 21), ormarker locus M12 (SEQ ID NO: 26).
 24. The method of claim 21, whereinsaid Sclerotinia sclerotiorum resistance allele is identified bydetecting a recurrent parent allele at marker locus M6 (SEQ ID NO: 15),a non-recurrent parent allele at marker locus M11 (SEQ ID NO: 20), and anon-recurrent parent allele at marker locus M12 (SEQ ID NO: 26) onchromosome
 7. 25. The method of claim 20, wherein the progeny plant isan F₂-F₆ progeny plant.
 26. The method of claim 20, wherein producingsaid progeny plant comprises backcrossing.
 27. A method of producing aplant of a green bean line exhibiting resistance to Sclerotiniasclerotiorum , comprising introgressing into a plant a Sclerotiniasclerotiorum resistance allele within a recombinant chromosomal segmentflanked in the genome of said plant by: (a) marker locus M1 (SEQ IDNO: 1) and marker locus M2 (SEQ ID NO: 7) on chromosome 2; (b) markerlocus M9 (SEQ ID NO: 8) and marker locus M10 (SEQ ID NO: 14) onchromosome 7; or (c) marker locus M11 (SEQ ID NO: 20) and marker locusM12 (SEQ ID NO: 26) on chromosome 7; wherein said introgressedSclerotinia sclerotiorum resistance allele confers to said plantincreased resistance to Sclerotinia sclerotiorum compared to a plant notcomprising said allele, and wherein said plant lacks a deleteriousallele genetically linked to said Sclerotinia sclerotiorum resistanceallele that confers undesirable seed color to said plant when present.28. The method of claim 27, wherein (a) said introgressed Sclerotiniasclerotiorum resistance allele is within a recombinant chromosomalsegment flanked in the genome of said plant by marker locus M1 (SEQ IDNO: 1) and marker locus M2 (SEQ ID NO: 7) on chromosome 2, and whereinsaid plant further comprises a further introgressed Sclerotiniasclerotiorum resistance allele within a recombinant chromosomal segmentflanked in the genome of said plant by marker locus M9 (SEQ ID NO: 8)and marker locus M10 (SEQ ID NO: 14) on chromosome 7 or marker locus M11(SEQ ID NO: 20) and marker locus M12 (SEQ ID NO: 26) on chromosome 7;(b) said recombinant chromosomal segment is flanked in the genome ofsaid plant by marker locus M11 (SEQ ID NO: 20) and marker locus M12 (SEQID NO: 26) on chromosome 7; or (c) said recombinant chromosomal segmentis defined by a recurrent parent allele at marker locus M6 (SEQ ID NO:15), a non-recurrent parent allele at marker locus M11 (SEQ ID NO: 20),and a non-recurrent parent allele at marker locus M12 (SEQ ID NO: 26) onchromosome
 7. 29-30. (canceled)
 31. The method of claim 27, wherein saidintrogressing comprises backcrossing, marker-assisted selection orassaying for said Sclerotinia sclerotiorum resistance. 32-33. (canceled)34. A green bean plant obtainable by the method of claim
 27. 35. Amethod of selecting a green bean plant with increased resistance toSclerotinia sclerotiorum comprising: a) crossing the plant of claim 1with itself or with a second green bean plant of a different genotype toproduce one or more progeny plants; and b) selecting a progeny plantcomprising said Sclerotinia sclerotiorum resistance allele.
 36. Themethod of claim 35, wherein selecting said progeny plant comprisesdetecting a marker locus genetically linked to said Sclerotiniasclerotiorum resistance allele.
 37. The method of claim 36, whereinselecting said progeny plant comprises detecting a marker locus withinor genetically linked to a chromosomal segment flanked in the genome ofsaid plant by: (a) marker locus M1 (SEQ ID NO: 1) and marker locus M2(SEQ ID NO: 7) on chromosome 2; (b) marker locus M9 (SEQ ID NO: 8) andmarker locus M10 (SEQ ID NO: 14) on chromosome 7; or (c) marker locusM11 (SEQ ID NO: 20) and marker locus M12 (SEQ ID NO: 26) on chromosome7.
 38. The method of claim 35, wherein selecting a progeny plantcomprises detecting nucleic acids comprising marker locus M1 (SEQ ID NO:1), marker locus M2 (SEQ ID NO: 7), marker locus M3 (SEQ ID NO: 2),marker locus M9 (SEQ ID NO: 8), marker locus M4 (SEQ ID NO: 9), markerlocus M10 (SEQ ID NO: 14), marker locus M6 (SEQ ID NO: 15), marker locusM11 (SEQ ID NO: 20), marker locus M8 (SEQ ID NO: 21), and marker locusM12 (SEQ ID NO: 26).
 39. The method of claim 35, wherein said progenyplant is an F₂-F₆ progeny plant.
 40. The method of claim 39, whereinproducing said progeny plant comprises backcrossing.